D40 Fuel Economy

[nathand22]

If you could work it out you could sell the idea and be rich because there will never be an exact formula and just adding a bit of weight will not necessarily effect you economy. I can drive around with the tub full and get the same economy figures as when the tub is empty, it may or may not be sustainable across the entire tank because of hills, wind, temps and a heap of other factors but it can be done. Adding weight on the outside may have some effect in that wind resistance may be effected but weight alone (the kind anyone here is adding in mods) is not a definite factor in changing economy.

If you want to get all technical then yes you are 100% right, BUT if i drive up and down the freeway to the ACT like i do, doing the same speed each day and driving in the pretty much the same way then all of a sudden throw over 200kg in the car i can tell the difference, yes i could negate that difference by changing my driving style and slowing down and not insisting that i maintain 120kph up every hill and by turning the cruise off and driving my self watching the scangauge every second.
Really lets face it if you drive in the same manor and add weight and roof racks and bigger tyres YOU ARE GOING TO EFFECT YOUR ECONOMY there is no two ways about it, I notice the difference all the time as some days i will just have a few small tools and one ladder and other days i will have 300 kg of sand and cement in the back or maybe three ladders and a few 6m long ally planks and i can tell how much extra fuel that uses.

lets just say that we did a test on an oval circut and we had the ute doing 100kph around it for 100 laps and then did exact same laps and exact same speed on the same day with the same temps and wind direction and humidity then added 200kg+ onto the exterior of the vehicle you would most definitely see a change in economy.
Myth busters did some testing with a tail gate up or down and with a hard cover or a net across the tail gate area, or windows up compared to windows down also with a/c on or off and saw that each one of those things made a difference to the economy.
All those factors can change the fuel economy but yes if you can negate the difference by changing the way you drive but who really wants to say "well i have approximately 238kg on today so i will drop my revs by 3% over a 200km distance and i will slow down from 110kph to 97kph and i will use $4.50less fuel blah blah" blah

 

[KraftyPg]

There is no reason to get technical to be right, the fact is that weight alone doesn't kill economy. Just like it's fact that the biggest effect on economy is the driver. Just like its fact that changing conditions will equal changing economy. No point getting technical about it because people don't like technical data that proves them wrong.

Look at how many people want to scream that DPF's kill economy, look at how many people want to lay the first blame of average economy on bigger tyres, look at how many people actually think cruise control is an economical method of driving. People don't want technicalities, they want someone to tell them that average or bad economy is Nissan's fault, the fault of mods or the faults of something else related to the ute, they rarely want to accept that fuel economy is and always will most effected by the steering wheel attendant sitting in the front seat

 

[nathand22]

Im not saying that the driver isnt the bigest factor in getting good or bad figures, What im saying is if you get an AVERAGE of lets say 20lph over say 5000km of driving like i do up and down the same stretch of freeway then all of a sudden you add extra shit to the outside or inside or where ever and take an average again over the same distance and from travelling on the same road you will see a difference regardless of how good or bad your economy is at the beginning.

Your just disagreeing for the sake of disagreeing, you must be bored.

 

[KraftyPg]

I'm not disagreeing, I'm just suggesting there is no reason to be technical about it because common sense explains things easier.

If I was disagreeing just for the sake of it I'd have made personal hits and told you it was you that was a dumbarse looking to blame someone else for the things you can't manage to achieve, but I kept such things away from it.

 

[steve1961]

Maybe they need to fit an economy gauge , something like was in the early crappadores , but seriously , I think it's a combo of all the above , driver , accessories , conditions , tire pressures , etc , have you ever forgot to " air up " after 4 wheeling ? See what that does to your economy

 

[siringo]

The one thing I know for sure is that I can stretch my fuel by driving slower.

This week I'm shifting before I get 2000rpm, around 1800 revs and crusing at around 1800 revs. Going up hills gently and rolling down in neutral.

I'm not doing any figures but I'll know if it's made a difference by how much I have in the tank at the end of today.

I usually fill up on Monday morning and by Thursday morning it's under 1/4 full, so if by Thursday morning it's at 1/4 full or better I will have found out how much fuel I can save by driving like that. It's bloody slow though, that's the only problem.

 

[nathand22]

No i am pretty confident that there is no way that i can achieve the figures steve gets in his day to day driving due to the fact that my car has different things on it like carrying an extra 250 kg and roof racks ect BUT if i wanted to drive down the freeway at 60kph for 400+km i could get better figures then him although that wouldnt be my normal day to day figures would it that would be me just trying to prove a point

 

[siringo]

Would be interesting to find out why some are getting great figures , and why some are getting crap ones , weather there's some common thread in both , or the good ones are just fluke engines

Yes exactly.

With the difference in fuel consumption between your truck and mine, the money i'd save on fuel, I could justify buying a new ute.

BUT!!! I wouldn't be surprised if my new ute, gave only fractionally better fuel returns than my current. It's areal crap shoot.

Steve I'm really interested to find out what happens once you fit all your after market gear. Could you please keep us updated??

 

[steve1961]

Yes exactly.

With the difference in fuel consumption between your truck and mine, the money i'd save on fuel, I could justify buying a new ute.

BUT!!! I wouldn't be surprised if my new ute, gave only fractionally better fuel returns than my current. It's areal crap shoot.

Steve I'm really interested to find out what happens once you fit all your after market gear. Could you please keep us updated??

Yeah I sure will , and as I pointed out , it will be done in one lump , so anything that happens will be quite noticeable , ill be happy if I can still achieve 10 Lts per 100 k

 

[nathand22]

The one thing I know for sure is that I can stretch my fuel by driving slower.

This week I'm shifting before I get 2000rpm, around 1800 revs and crusing at around 1800 revs. Going up hills gently and rolling down in neutral.

I'm not doing any figures but I'll know if it's made a difference by how much I have in the tank at the end of today.

I usually fill up on Monday morning and by Thursday morning it's under 1/4 full, so if by Thursday morning it's at 1/4 full or better I will have found out how much fuel I can save by driving like that. It's bloody slow though, that's the only problem.

thats what im saying i have driven around watching the scangauge, putting it in neutral on the down hills, trying to be gentle on the throttle, not labouring the motor by being in a high gear all the things that does show improvement, but when im doing all those things and getting figures much higher then some one else who says they are just driving it at 110kph and changing gears at 3000rpm i have to think what else can be a factor?? and the obvious things are the weight, wind drag, and bigger tyres.
When my absolute best figures from trying to get the best fuel economy are still 1lph off some one else's average from not even thinking about economy there has to be something in it and not 100% the driver

 

[KraftyPg]

BUT if i wanted to drive down the freeway at 60kph for 400+km i could get better figures

Ok time argue for arguments sake. At 60kph you are unlikely to get better economy than anyone unless it's a short downhill stretch when you can keep your foot off he accelerator

 

[steve1961]

You see , iam not doing any of that , just driving normally , maybe ill reposition my road cam to view the instrument cluster and give you a 5 min vid of urban driving

 

[KraftyPg]

Actually trying to drive for better economy can effect it more than driving normally, but that obviously depends on what ones normal driving is like.

 

[siringo]

You see , iam not doing any of that , just driving normally , maybe ill reposition my road cam to view the instrument cluster and give you a 5 min vid of urban driving

That'd be fun to watch anyway, see how mad you Melbourne drivers are ;-)

 

[siringo]

thats what im saying i have driven around watching the scangauge, putting it in neutral on the down hills, trying to be gentle on the throttle, not labouring the motor by being in a high gear all the things that does show improvement, but when im doing all those things and getting figures much higher then some one else who says they are just driving it at 110kph and changing gears at 3000rpm i have to think what else can be a factor?? and the obvious things are the weight, wind drag, and bigger tyres.
When my absolute best figures from trying to get the best fuel economy are still 1lph off some one else's average from not even thinking about economy there has to be something in it and not 100% the driver

Tried driving wiothout the hand brake engaged?

 

[nathand22]

Would be interesting to find out why some are getting great figures , and why some are getting crap ones , weather there's some common thread in both , or the good ones are just fluke engines

Maybe it has something to do with the injector "codes" that the computer reads from each injector to adjust the fuel pressure to each cylinder?? Apparently the tolerance set in each injector is quite low from denso and they dont have to be as exact as they use to be due to the computers ability to adjust pressure to each individual injector, also from what i have heard if you do match the injectors better you can fool the ECU in the are of coding by telling it that the codes of each injector are different to what they really are, effectively getting the same results as some "power chips"

Companies like "Baileys Diesel Group" can do this with there "blueprint reco injectors"

Here is a link to a short video 2:34min to explain it better form Baileys diesel
http://www.youtube.com/watch?feature=player_embedded&v=880TC1cBPDM#at=17

and part 2 = 1;25min

http://www.youtube.com/watch?feature=player_embedded&v=IMk4WfuVlVc

 

[siringo]

Maybe it has something to do with the injector "codes" that the computer reads from each injector to adjust the fuel pressure to each cylinder?? Apparently the tolerance set in each injector is quite low from denso and they dont have to be as exact as they use to be due to the computers ability to adjust pressure to each individual injector, also from what i have heard if you do match the injectors better you can fool the ECU in the are of coding by telling it that the codes of each injector are different to what they really are, effectively getting the same results as some "power chips"

Companies like "Baileys Diesel Group" can do this with there "blueprint reco injectors"

Here is a link to a short video 2:34min to explain it better form Baileys diesel
http://www.youtube.com/watch?feature=player_embedded&v=880TC1cBPDM#at=17


and part 2 = 1;25min

http://www.youtube.com/watch?feature=player_embedded&v=IMk4WfuVlVc

Very interesting, i'm going to need to do some reading.
Thanks.

 

[nathand22]

Here you go guys look at this video it give examples of how heavy machinery can become more economical NOT from purely changing how the diesel engine is used but how the fuel system is built or maintained, yes this is an advert of sorts but the figures they are sprouting and the guarantee they offer has to make you think there is allot more to the difference in individual fuel figures then just saying "your a dumb arse and you dont know how to achieve good fuel consumption" like some would suggest

http://www.youtube.com/watch?feature=player_embedded&v=DPa3_H00vDI#at=269

 

[nathand22]

Here is a link to their web site and to the Navara section as they are now doing "blueprint reco" injectors for our YD25 engine with double the warranty of new and at less the half the price.

http://www.baileysdiesel.com/on-highway/common-rail/nissan/navara/


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[steve1961]

Here is a link to their web site and to the Navara section as they are now doing "blueprint reco" injectors for our YD25 engine with double the warranty of new and at less the half the price.

http://www.baileysdiesel.com/on-highway/common-rail/nissan/navara/


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well after watching , maybe some of us that do have the better economy , have a more matched set of injectors then the std variance , by fluke